Blown Opportunity: We Install and Dyno a Magnuson Blower and Trick Flow Heads on an LS3 Corvette

The LS3 is a fantastic platform that readily accepts a variety of mods to boost its factory rating of 430 horsepower. Heads, cams, exhaust, power adders--you name it, the LS3 loves it! Our Grand Sport baselined on the Antivenom Performance Dynojet chassis dyno at 394 horsepower, and 397 ft.-lbs. of torque.

On a C6, the power steering rack has to be removed to get the balancer off for a cam swap. This is done after the front sway bar is lowered away from the frame.

The valvetrain on any factory LS engine uses a “net lash” design, meaning they are not adjustable. The benefit of this is ease of installation and removal. Simply remove all eight rocker arm bolts, and the rockers and stand will come off the head as an assembly.

Once the airbox is out of the way, the intake manifold is unbolted and removed. The factory throttle body will be transferred to the blower intake assembly.

One of the three main components in our install is Magnuson’s MP2300 TVS kit (part number: 012362265BL). The unit displaces 2.3 liters and features TVS design helical rotors, along with a race inspired water-to-air intercooler system to keep heat soak at a minimum.

After unbolting the front accessory drive and exhaust headers, we pulled the heads. While the factory LS3 heads are great performers, they can’t match the flow capacity and efficiency of the Trick Flow units we’ll be installing. Factory LS head bolts are one time use only, and they aren’t really up to the challenge of a boosted application. For superior clamping force, and to reduce the stress on the threads in the block, we installed ARP’s LS head stud kit (part number: 234-4317). Because head studs don’t twist like bolts when being torqued, you get a much more accurate and consistent torque loading. In addition, they only stretch on their vertical axis when torque is applied, meaning less stress on the fastener itself. They’re also reusable without need to be changed if the heads ever have to be removed again.

Naturally aspirated LS engines typically use three layer (left), MLS (Multi-Layer Steel) head gaskets, opposed to the composite type gaskets typically used on older generation engines. MLS gaskets feature superior sealing along with better longevity through the constant heat cycles of an engine. For boosted applications, it’s recommended that you use a four layer (right) MLS gasket, similar to what’s used on the LS9 and LSA factory engines. These gaskets will have “SC” stamped on them next to the part number. The extra layer helps with sealing under boost.

To make the most of our Magnuson supercharger, we’re installing a set of Trick Flow GenX 255 Cylinder Heads for GM LS3 (part number: 32610001-C01). The Trick Flow heads feature a raised intake port (requiring longer than stock pushrods) that give the air/fuel mixture a straighter shot at the intake valve, allowing for more velocity through the port, meaning a higher volume can be flowed into the cylinder while the valve is open. They’re CNC-ported for maximum efficiency, and are compatible with any LS3-style rectangular port intake. Even with the raised ports, they still work with factory LS3 intakes as well.

A closer look at the Trick Flow heads.

One of the extra things you’ll need for swapping heads on any 2008-up LS series engine is a pair of these coolant plugs (part number: 12602540) and a pair of the necessary bolts to install them (part number: 11588714).

Before the cam can be removed, the timing chain tensioner/dampener has to be pinned back to relax tension on the chain. Then the cam sprocket can be unbolted, and the camshaft removed.

To get the most power out of the heads and blower, an Antivenom Performance special blower cam, custom ground by Comp Cams was installed. It features a wide lobe separation angle, and can produce more power than a factory LS9 cam. If you want something not in the catalog, custom grinds from Comp Cams can be ordered directly through Summit Racing. Just call for specific pricing.

The factory LS3 cam features a single bolt cam sprocket, while the new camshaft requires a three bolt sprocket and and a cam bolt set from ARP.

Another item that’s necessary when swapping a cam into an LS is this special alignment tool for the timing cover. If you try to reinstall the cover without using this tool, you’ll end up with an oil leak.

The Trick Flow heads require longer than stock pushrods, so we ordered a set of Trick Flow pushrods (part number: 21407750). The 7.750-inch pushrods are made of 4130 chromoly steel and are 5/16-inch in diameter. Stiffer than the factory pushrods, these will enhance valvetrain stability (especially at high rpm) because they have less flex, especially under high rpm and increased valvespring loads.

The Magnuson kit comes with this tool, which is used to “pin” the crank pulley/harmonic balancer on the crank snout. Unlike their Gen I ancestors, LS engines don’t have crankshafts with keyways to keep the balancer from rotating on the crankshaft snout. Under load from turning a blower, the balancer would start to turn on the snout, and eventually work its way off. The tool is made so you can’t drill too deep into the crank snout, ensuring proper depth for the dowels.

Using the tool, two holes will be drilled in the crank snout (while the balancer is installed) and the two included dowels tapped in place. Now the balancer is secure against any unwanted rotation.

Fresh, non-platinum plugs are installed and gapped to .035-inch. Regular plugs are used because platinum plugs can only be gapped at the spark plug factory. The factory gap of .045-inch is too wide for boosted applications, where the extra pressure from the blower will literally blow the spark out.

The factory crossover tube (left) has to be swapped out for the tube included in the Magnuson kit (right) to relocate the outlet nipple.

These new intake manifold gaskets also come with the supercharger kit.

The reservoir for the power steering pump has to be relocated using the included relocation bracket.

To install the blower, the fuel injector rails and intercooler lid must be removed first. Then the blower can be set down on the engine and the retaining bolts torqued down. For reinstalling the intercooler top, the engine cradle has to be partially unbolted, so the engine can be tilted back to make enough room to reinstall the rear cover bolts.

The racing inspired water-to-air intercooler sits on top of the blower rotors. The air is first compressed by the rotors and then cooled as it runs through the intercooler. The efficiency of the Magnuson intercooler ensures the air will be as cool as possible entering the cylinders, even in the middle of summer. Magnuson took proven methods from Formula One and NASCAR in developing this intercooler.

The factory throttle body is transferred to the blower assembly. The blower also has all the hookups for the factory vacuum and other accessory lines.

To clear the blower, the coils have to be relocated to the valve covers, using the included coil brackets.

The heat exchanger for the intercooler is mounted in front of the radiator. This keeps the liquid nice and cool so the air charge temp will stay down. This helps the blower stay immune from the power robbing problems from heat soak.

The reservoir for the intercooler is mounted on the passenger side up top, while the pump for the intercooler is mounted down low by where the horn mounts. The Magnuson supercharger kit comes with all the necessary brackets to relocate factory parts and mount necessary ones like this.

The supercharger kit also comes with a new air intake box, including a high-flow air filter.

Here’s how it looks once everything’s bolted back on the engine. After Antivenom’s Greg Lovell inputted the necessary computer tuning (required with the Magnuson install) the Grand Sport was strapped back on the dyno to see what we had. Thanks to the Trick Flow heads and Magnuson blower, the GS now had a whopping 600 horsepower at the rear wheels, and 519 pound-feet of torque. And that was only with 4.5 psi of boost going into the engine, meaning this animal has a lot more in it. With this kind of performance, who needs a ZR1?!

We put the Magnuson MP2300 TVS kit to the test on a C6 Corvette Grand Sport. Knowing that the Magnuson kit would welcome the best-flowing heads possible, we also grabbed a pair of Trick Flow 255 Gen X CNC-ported heads. Together with a custom ground cam spec’d out by our install shop, Antivenom Performance in Seffner, FL, this 2011 Corvette would prove to be anything but average.

See how the install came together in the slideshow below and then get the final power numbers. But you may want to find something to hold on to first!